Document FR-A-2 592 825 describes an assembly for tightly laying such a covering on an element such as a cable or two cables that are electrically and mechanically interconnected. That assembly includes a rigid tubular support of dimensions designed so as to enable it to be mounted freely on the element, and the support is provided with a flexible film having a low coefficient of friction. The film is fixed to one end of the support and it extends freely over its outside surface. The covering is mounted on the laying assembly by being expanded so as to be positioned over the element. It is laid and simultaneously shrunk in place on the element by taking away the laying element from beneath the covering, while manually holding the covering in position over the element. As the rigid support is taken away, the film turns inside-out beneath the in-place shrunk covering. The film is taken away in turn from beneath the fully shrunk and in-place covering.
Document FR-A-2 706 976 discloses a laying assembly of the above-specified type but in which the flexible film having a low coefficient of friction is not fixed to the end of the support but is associated with means for guiding it and driving it around said end and over the inside surface of the support as the support is taken away from beneath the expanded covering that it carries.
The problem posed by such laying assemblies, or by any other laying assembly that can be taken away from beneath the expanded covering thereon, is that the covering is not always laid accurately on the desired location of the element, but moves to a greater or lesser extent together with the laying assembly which needs to be pulled hard in order to take it away.
To avoid such a problem, document FR-A-2 724 444 proposes in particular adopting a laying assembly of the kind described above but in which the rigid support is in the form of two mutually independent tubular portions which are placed end to end for receiving the expanded covering over both of them and which are taken away from beneath the covering one after the other, with means then being provided for fixing to the element the second of the two portions that is to be taken away from beneath the covering, while the first portion is itself being taken away.
The dispositions provided thereby are generally satisfactory, but they nevertheless require sufficient space in both directions along the element at either end of the assembly for laying the covering on the element to enable first one and then the other of the two portions to be taken away. They make it necessary to use a two-portion support even when it would be advantageous, if possible, to use a laying assembly having a support that is in a single portion, particularly for reasons associated with the overall time of the operations concerned and with the resulting overall cost. However, it is sometimes impossible to ensure sufficient space in only one or other of the two directions and thus impossible to use such dispositions, and in any event it is advantageous if only one space needs to be provided in one or other of the two directions in which the laying assembly can be taken away. These considerations mean that, whenever possible, it is preferable for the laying assembly to be constituted by a single portion, in which case it cannot be fixed to the element.